Underground mining is conducted at the Mavres Petres deposit, along the Stratoni fault which dips 45 degrees to the south. The main mining method is drift and fill, in the upper zone the stope sizes are 4 x 4m and in the lower zone the stopes are larger at 6 x 6m. The Mavres Petres deposit is open down dip and to the west. The ore is processed in a conventional differential flotation processing plant. Separate lead and zinc concentrates are produced which are bagged and then transported to smelters either via the Stratoni or Thessalonoki ports.